Help identify 1940’s Omega

Empty screw holes at 5 and 10 (as your photo is oriented with the stem roughly at 6) are for case clamp screws or clips on this 30mm movement.
Argentina origin will make a model number difficult but the CK2186 had a 37.5 case diameter with the 30mm movement from about this time.

No gasket, no bumpers that I have seen from this time and putting dimples in the dial gives me shivers. Perhaps this was assembled/adapted in Argentina.

This listing shows case mounting in the CK 2186 and note the movement/case serial numbers are very close to yours.

I'm the village idiot but we do have some wonderful experts and watchmakers here that I hope join in!
Good luck, I hope you can modify the case clamps somehow as opposed to bending the casebook.

No case screws nor clamps needed with this case design...
The movement sits in some sort of "tub" caseback - was an early attempt to protect against moisture and dust. Not uncommon.
The 2-part-case works like a box...
I have got 2 similar watches in my collection, but the more similar unfortunately without EoA, so I don´t know the ref-nr.
One I know for sure is ref 2105:

This is the caseback of ref 2105 with same construction features but the upper case part looks different to that of OP´s watch.

There are too many ref. of that era - you only would know for sure by an EoA which is not available any more.